Forging apparatus



Dec. 26, 1950 J. LAFONT 2,535,295

FORGING APPARATUS Filed June 50, 1947 3 Sheejs-$heet 1 Dec. 26, 1950 LAFONT 2,535,295

FORGING APPARATUS Filed June 50, 1947 3 Sheets-Sheet 2 Fig :5,

Dec. 26, 1950 Filed June 30, 1947 J, LAFONT 2,535,295

FORGING APPARA'IUES 3 Sheets-Sheet 5 Patented Dec. 26. 1950 2,535,295 FORGING Aernan'rns Jean Lafont, Saint-Chamond, France, assignor to Compagnie des Forges etAcieries'de la Marine efldHornecourt, Paris, "France, :a joint-stock corporation Application June 30, 1947, Serial In France July 5,

2 Claims. (o 29-6) The object of the present invention is to provide animprovement in the forging apparatus described in copendin'g application Serial No.

G0 '0,3"78,"filed' June 19, 19%5, by Francois Meley.

"'Tlfie'"fibre forming method of said'apparatus essentially consists of using blanks initially provided with enlarged portions or excrescences to provide the flared out or enlargedportions in the final part which are separated by restricted sections to'form the narrow sections of such part. "Such'a blank was either turned or forged sectionafte'r section in one or more steps according to the number of said excrescen'ces.

Thusl'the forging of any part involved first of all preparing a blank therefor.

It" was stated in'said co-pending application that the apparatus could also be used for obtaining blanks comprising enlarged sections or flanges from an initial cylindrical blank. It is simply necessary for such purpose to grip the tralfswages are modified so that it is possible tem oreniy to neutralize their action and leave them in position during the formation of the enlarged sections on each side of the central swages by a longitudinal forging operation.

In this way, preparation of the enlarged sections in the blank is effected in a first stage of the forging operation which thus includes two separate consecutive stages.

The present invention makes it possible to perform successively both stages of the operation upon a cylindrical blank without having to modify any part of the apparatus between the stages.

The accompanying drawings show by way of example one form of embodiment of a device according to this invention.

Figure l is a diagrammatic view partly in cross section, on line II of Figure 2.

Figure 2 is a cross sectional view on line IIII of Figure I.

Figure 3 is a view similar to that shown in Figure l at the start of the forging operation.

Figure 4 is a View similar to Figure l at the end of the first stage of the forging operation, and

Figure 5 is a view similar to Figure '1 at the end of the second stage of the forging operation.

In the various figures of the drawings like reference characters indicate like parts.

Referring particularly to Figures 1 and 2, the forging apparatus is constructed as follows:

As set forth in the above-mentioned co-pending application, the blank is locked on both sides of the site where the crank is to be forged by two pairs of half swages 8, I 0 and 9, II." The lower swages 8, 9 rest upon the cradles M which are capable of sliding in the direction of the length of the blank upon the slides I, l. The cradles have inclined ramps 15 cooperating with ramps'lfi provided on the upper cross barl3of the'apparatusf k Between the two swages 8, l0 and 9, II "the blank is grasped between a central upper half swage l and'a central lower half swage l2; Also as described in the co-pen'ding applicationthc lowerhalf'swage12 is carried by a vertical hydraulic piston l7. But'while according to the co-pending application the upper half swage I is fixed to the upper cross bar I3 of the' apparatus, according to'the present invention, this halfswage is vertically movable to 'aoe'rtain degree with rotation to the crossbar I 3: Inother words, there is provided a lost motion between said central swage and the cross bar I3. For this purpose the upper halfswage'l has a hydraulic-cylinder in the top portion thereof in which a piston is received wl'iichi sfiized to the cross bar l3 and whose diameter is less than that of the piston ll carrying the lower half swage I2.

The upper half swage l is guided vertically by the rods l which are fixed to the cross bar l3. The cylinder of the piston 2 communicates with a relief valve 4 for allowing the liquid to escape from the cylinder at a predetermined pressure. The valve 4 is mounted on the cross bar 13 and is connected to the cylinder of the piston 2 by an articulated tube 6. Another analogous conduit 5 connects the same cylinder to a liquid supply under the control of a manually operable valve 3.

The device operates as follows:

The initial starting blank is cylindrical and.

has a uniform diameter throughout its length,

" which diameter corresponds to the intermediate sections which are not to be subjected to any deformation during forging. This blank, in the forging apparatus is processed in the following manner:

1st. The various swages being open and the cradles l adjusted to the required spacing, the cylindrical blank is placed on both of the lowermost outer half swages 8 and 9.

2nd. The blank is then locked in the apparatus as shown in Figure 3 by bringing the upper outer half swages it and H into engagement with the blank which is thus firmly clamped.

The central portion of the blank is thereafter clamped. For that purpose, after adjustment of the relief valve 4, the lower central half swage 2 and then the upper central half swage l, the hollow cylinder of which has preliminarily been filled with water, are successively caused to engage the blank. The apparatus is thus in condition for the two stage forging operation.

It is to be observed that in such condition and throughout the first stage (formation of the enlarged sections) the blank is not subjected, opposite the upper central half swage I, to any bending stress, since the lower central half swage l2, through the medium of its pressure-piston and its return pistons (which restrict the upward stroke thereof) is adapted to, amply take up the locking reaction of the upper central half swage 5, until the latter has engaged the upper crossbar IS. The formation of the enlarged sections at each side of the central half swages is thus efiected in a very uniform manner and without any deviating strains.

3rd. The blank is then subjected to the actual forging step, in two successive stages without any discontinuity therebetween.

First stage (Figure 4) By means of the press, the upper cross member i3 of the apparatus is lowered. Both central half swages i and i2 remain stationary. Only the piston 2 is retracted into its cylinder, creating on the upper central swage a reaction (which is a function of the adjustment of the valve 4) which firmly clamps the blank.

The outer swages 8 to l l firmly clamp the blank and are driven by the cradles 1, thereby driving the metal forming the blank against the side faces of both central half swages, thus automatically forming the enlarged sections which are to form the webs. This first stage is completed when the upper cross member l3 engages the top of the upper central half swage i.

Second stage (Figure At this moment, the second forging stage commences.

The upper central half swage i now in contact with the cross member 13 becomes operative and moves downwardly with said cross member. Under the action of the press it causes the blank to be deflected downwardly, driving the lower central half swage 12 which in turn is operative to lock the restricted portion of the blank by means of its relief valve.

During this time, the outer swages moving in directions converging towards the center, press the enlarged sections between their own walls and those of the pair of central half swages and thus form the webs thereby uninterruptedly converting the cylindrical blank into a bent element having flared out webs.

The operation is completed when the movable cross member I 3 stops on the adjusting shims carried by the cradles. It then only remains to raise up the cross member and remove the forged lank from the swages.

I claim:

1. In an apparatus for forging a crank shaft from a cylindrical blank the combination comprising spaced lateral swages which lock the blank on both sides of the site of the crank to be forged, means for guiding said lateral swages along the longitudinal axis of said blank, a central divided swage for locking said blank at the site of the crank pin to be forged, means guiding said central swage transversely to the longitudinal axis of said blank, means operatively connecting said lateral swages to said central swage and a lost motion connection between said central swage and said lateral swages.

2. In an apparatus according to claim 1 said lost motion connection comprising a hydraulic cylinder and a piston therefor interposed between said central swage and said lateral swages and a relief valve for said hydraulic cylinder.

JEAN LAFON'I.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 854 Great Britain Mar. 8, 1875 2,423 Great Britain Oct. 6, 1860 779,043 France Mar. 28, 1935 

